Method expect

src/parser.ts:440–445

(value)

    // If not, an exception will be thrown.

    expect(value) {
        const token = this.nextToken();
        if (token.type !== Token.Punctuator || token.value !== value) {
            this.throwUnexpectedToken(token);
        }
    }

    // Quietly expect a comma when in tolerant mode, otherwise delegates to expect().